Reverse total shoulder surgery helps many patients when all else fails

Friday

Oct 19, 2012 at 2:30 PMOct 19, 2012 at 2:43 PM

Every year, orthopedic surgeons in the United States replace thousands of damaged shoulder joints. The shoulder is the third most common joint being replaced in the U.S. The conventional artificial joint looks similar to the normal shoulder joint: a ball located at the upper end of the arm bone fits into a cup in the shoulder socket.

Michael MacKay, M.D., Special to The Oak Ridger

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The reverse surgery benefits many people who have a severe form of arthritis of the shoulder.

Every year, orthopedic surgeons in the United States replace thousands of damaged shoulder joints. The shoulder is the third most common joint being replaced in the U.S. The conventional artificial joint looks similar to the normal shoulder joint: a ball located at the upper end of the arm bone fits into a cup in the shoulder socket. The design of this device relies on the rotator cuff tendon to hold the joint in place and provide normal movement in an arc of nearly 360 degrees around the body.

Conventional shoulder replacement surgery has been performed in the U.S. since the late 1970's. It works well for most people, providing relief of pain, improvements in strength and motion, and restores function.

However, a relatively new procedure is relieving pain and improving function in people who have not benefited from conventional surgery. It is called “reverse shoulder replacement.” When a person develops painful arthritis, but also has a very large, irreparable rotator cuff tear (a condition called "cuff tear arthropathy"), a conventional replacement will fail to restore the motion and stability required for success. It demands a considerable change in the mechanics of the joint. The reverse surgery benefits many people who have this severe form of arthritis of the shoulder. Most patients are over age 60 when the reverse procedure is recommended.

The ball and socket used in reverse total shoulder replacement are — as the name of the procedure states — in reverse positions. This design relies on the large deltoid muscle, rather than the rotator cuff, to hold the joint in place. The joint has its limitation because the one large muscle cannot completely replicate the normal rotation provided by the functioning rotator cuff, but the ability to raise the arm above the head is a tremendous benefit to daily self care and function.

The Reverse Procedure

An orthopedic surgeon makes an incision that is approximately six inches long over the front of the shoulder. He or she then removes damaged bone and soft tissues. Finally, the surgeon screws a metal ball into the socket, secures a plastic cup to the upper end of the arm bone, and reattaches soft tissues. A general anesthesia is required, but many surgeons request an additional nerve block to assist their patients pain relief after surgery. Most people are able to sit up, walk and eat on the day of surgery and remain in the hospital for one to three days.

The recovery period generally lasts about six months. However, strength and range of motion can continue improving up to one year from the time of the surgery.

Encouraging Results

Reverse shoulder replacement surgery offers pain relief and improved range of motion in patients who previously had no other option. The pain relief is comparable to the results that people experience when they have an intact rotator cuff and undergo conventional shoulder replacement surgery.

However, patients who undergo reverse shoulder replacement tend to have severe problems in their shoulder joint. Only 50 to 75 percent of their normal range of motion will return in those cases.

Is shoulder replacement right for you? That depends on many other factors, which your surgeon should discuss with you. Factors, such as previous injuries and surgery to the shoulder, past and current health conditions, medications such as blood thinners, will help your surgeon determine the optimal timing of surgery.

Are you emotionally prepared to undergo the rigors of therapy? Start off by finding a surgeon whom you trust and can have a cooperative relationship with. Referrals from family members and friends, as well as your primary care doctor are excellent ways to begin the process. Ask questions until you are satisfied that shoulder surgery will improve your quality of life and all other treatment options have been exhausted, then you will in all likelihood come away with a very satisfying result.

How the Shoulder Works

The shoulder is a complex unit that actually consists of two joints: The well-known ball-and-socket joint and the smaller, and less considered acromioclavicular joint, which is between the clavicle (collar bone) and scapula (shoulder blade). The joints are held together and supported by important ligaments, and tendons called the rotator cuff. Cartilage lines the surface of the bones and allows them to glide upon each other. Bones that make up the shoulder are the humerus (large upper arm bone), the scapula (shoulder blade), and the clavicle (collarbone). At the top of the humerus is a ball that fits into the glenoid (socket). The acromioclavicular joint creates an arch above the humerus to provide stability to the ball of the humerus.

The rotator cuff tendon is a complex interaction between four muscles that helps people raise their arms from the sides and rotate their shoulders in all directions. It plays an important role in conventional shoulder joint replacement, as well as normal shoulder function. However, it frequently is torn or damaged beyond repair and causes a great deal of difficulty with movement and strength. The deltoid muscle is the largest and strongest shoulder muscle, and people use it to lift their arms once the arms are away from the sides. It plays a major role in reverse shoulder replacement.

About the Author: Michael A. MacKay, M.D., is a board-certified orthopedic surgeon on the staff of Methodist Medical Center of Oak Ridge. He obtained his bachelor of science and medical degrees from Wayne State University in Detroit, Mich., graduating in the top 5 percent of his medical school class. Dr. MacKay completed an internship in general surgery and a residency in orthopedic surgery at William Beaumont Hospital in Royal Oak, Mich. He has published articles in major orthopedic journals and is a member of the American Academy of Orthopedic Surgeons, Tennessee Medical Association, Tennessee Orthopedic Society, Roane-Anderson County Medical Association and American Medical Association.